Have I been doing it wrong

[Bryan Bennett]

When I bought the Hegner way way back,I was told to release the knob that holds the top clamp about half a turn so that the top clamp can move a little.I have been doing this when I have the quick release clamp on.Should I have turned the knob tight on to the top of the quick clamp so that it was rigid?. :?:

Bryan

 

[scrimper]

In the Hegner manual it does advise to leave it tight, but I have always done as you do and left it to move just a little, I feel that it has got to be better to be able to move as this helps to keep the blade cutting parallel.

I assumed that they suggest keeping it tight to help with refitting the blade on piercing cuts.

 

[Bryan Bennett]

Thank you scrimper for you prompt reply.

Bryan

 

[martinka]

I do the same. Not as much as if I was using a standard clamp, just enough for the clamp to move a touch. If it's too much, I can hear it rattle very slightly. This was something I decided to do when I was breaking a lot of blades, though whether it had any effect I don't really know, maybe it was the placebo effect.

 

[Chippygeoff]

I am not sure if there has been a miss print in the Hegner manual, I can find nothing in mine relating to the tension with regard to the knob on the top clamp. It is a misconception that the knob has to be tightened up to the blade clamp. This is wrong. I spoke to Christ in the technical department of Hegner and he told me to tighten the knob onto the clamp and then undo it 1/4 to 1/2 of a turn. The idea of tightening it up for certain cuts is rubbish. I do 100s of intenal and external cuts every week and never had a problem, spot on every time.

 

[martinka]

From the Hegner website, for the Quick Clamp:

"Specifications
When fitting a standard blade clamp into your Hegner scrollsaw the top arm knurled screw should be adjusted so as loosely retain the blade clamp to prevent it being ejected should the blade break. The standard blade clamp MUST be allowed to pivot on their sharp edge to ensure the blade is kept perfectly straight and vertical while the arms oscillate.

However the Quick Clamp should be rigidly fixed in the top arm – there are rotating bearing surfaces within the quick clamp which allow the blade to pivot, maintaining the correct geometry, while being securely held."

 

[Bryan Bennett]

According to the Hegner site I have been doing it wrong.I had not seen the comment under the Quick Clamp saying that it had to be rigid because there were factors within it to cut correctly.I have had the Q/C for ages so I will now have it rigid and see what happens.I thought that I put a thank you to Martin on but had'nt.THANK YOU Martin

Bryan

 

[scrimper]

I spoke to Christ in the technical department of Hegner

Lol I always knew Hegner were good! now I know why! or is it a typo.

Sorry I just could not resist, it made me smile!

 

[Bryan Bennett]

Thank You Scrimper you made smile,surprising how the letter "t" can change the meaning.

Bryan

 

[scrimper]

From the Hegner website, for the Quick Clamp:

"Specifications
When fitting a standard blade clamp into your Hegner scrollsaw the top arm knurled screw should be adjusted so as loosely retain the blade clamp to prevent it being ejected should the blade break. The standard blade clamp MUST be allowed to pivot on their sharp edge to ensure the blade is kept perfectly straight and vertical while the arms oscillate.

However the Quick Clamp should be rigidly fixed in the top arm – there are rotating bearing surfaces within the quick clamp which allow the blade to pivot, maintaining the correct geometry, while being securely held."

Well now I am really confused!

I have just been out to my workshop to study my quick clamp and it simply has an allen grub screw on one side and the threaded bolt with knurled knob on the other which tightens the blade, there are no rotating bearing surfaces that I can see?

I presume we are talking about the same thing? In my Hegner manual it is called a piecework clamp, it does state that it should be locked in place but the reason for doing this is given as "to save time when changing the sawblade!" No mention is made of rotating surfaces?

 

[martinka]

Scrimper, if you completely unscrew the knurled knob, you will see there is a small rotating piece in the end of the thread.

Martin.

 

[scrimper]

Scrimper, if you completely unscrew the knurled knob, you will see there is a small rotating piece in the end of the thread.

Martin.

Not in mine there isn't! I particularly took it out to examine it. I can only assume mine is an earlier version? I bought my Hegner in Dec 1999.

With the clamp out of the saw and the knob tightened the blade is locked in the clamp, there is zero movement.

I just looked at the receipt and it cost £436 inc vat (it is a Multicut variable speed)

 

[martinka]

scrimper, doesn't your quick clamp have the piece in the end of the thread, shown in the pics below? The more I look at that clamp, the more I wonder what they intended with it. As you rightly say, the blade can't move between the clamping screws as the blade is backed into a slot. But as ChrisR points out, the rotating part will stop the blade twisting as it is tightened in the clamp, so why the description on the Hegner website?

Martin.

 

[scrimper]

I am going to pop across to the workshop and have another look but I am sure it does not.

 

[scrimper]

No it is threaded to the end.

 

[Bryan Bennett]

Scrimper the one I have is different to yours,mine a small piece unthreaded at the end of the screw.It is like the one that Martin has posted.

Bryan

 

[scrimper]

This probably explains why the reason for having the top clamp tight was only to make it easier for blade changing whilst new information from Hegner suggests it is now to allow some rotation, due to the special bit fitted to the end of the knurled bolt on newer designs. Mine is obviously the old style.